Tympanostomy tube placement is the most common surgical procedure performed on children. In 1994, 556,000 children under age 15 underwent this procedure, which requires general anesthesia. One recent study evaluated the indications for surgery in over 6000 children who had been recommended for the procedure by their physicians and found that almost one-quarter of proposed tympanostomy tube placements may be clinically inappropriate. While many guidelines exist to facilitate clinical decision making, physicians often resist using them because of a concern that they do not inadequately account for individual patient variability. No study of appropriateness has examined the extent to which decisions made by practicing physicians deviate from evidence-based guidelines, the reasons physicians might give to explain any such discrepancies, and the extent to which those reasons justify deviations from the guidelines. We propose to develop and validate measures of quality to assess the appropriateness of the use of tympanostomy tubes in children. We will create evidence-based appropriateness guidelines with the assistance of a nationally-representative expert physician panel, which will be constituted by collaborating with pediatric and surgical specialty societies. We will derive quality measures from those guidelines and apply them retrospectively to a large, economically, racially, and ethnically diverse population of children who underwent the procedure. With the collaborative support of pediatricians and otolaryngologists at 5 New York metropolitan area hospitals, we will assess the appropriateness of approximately 1250 tympanostomy tube placements. For a sample of cases, we will interview surgeons and primary care physicians to ascertain factors not included in the guidelines that the physicians believed justified doing the procedure. We will also interview parents to understand their role in the decision to perform surgery. We will validate the justifications offered by the treating physicians by reconvening the expert physician panel and asking them to rate the appropriateness of the reasons given for deviating from the guidelines. We will revise the guidelines to incorporate the additional factors determined by the panel to be appropriate extenuating circumstances to produce quality measures with enhanced validity. Finally, we will examine the relationship between appropriateness and various patient, parent, and physician attributes.